Walnut bootloader fix
From: David Gibson <hidden>
Date: 2001-09-06 01:26:10
The following patch adds code to the "simple" bootloader to disable the ethernet controller on the Walnut board before booting the kernel. This is necessary on the Walnut I have, at least, or the EMAC has a tendency to DMA broadcast packets into the kernel text. diff -urN ../linuxppc_2_4_devel/arch/ppc/boot/simple/embed_config.c linux-bungo/arch/ppc/boot/simple/embed_config.c
--- ../linuxppc_2_4_devel/arch/ppc/boot/simple/embed_config.c Fri Aug 31 13:08:41 2001
+++ linux-bungo/arch/ppc/boot/simple/embed_config.c Thu Sep 6 11:25:24 2001@@ -638,6 +638,8 @@ */ #define BOARD_INFO_VECTOR 0xFFFE0B50 +#define PPC405_EM0MR0_ADDR 0xEF600800; + void embed_config(bd_t **bdp) {
@@ -646,6 +648,7 @@ bd_t *bd, *walnut_bd; bd_t *(*get_board_info)(void) = (bd_t *(*)(void))(*(unsigned long *)BOARD_INFO_VECTOR); + volatile u32 *em0mr0 = (volatile u32 *)PPC405_EM0MR0_ADDR; bd = &bdinfo; *bdp = bd;
@@ -668,5 +671,14 @@ bd->bi_busfreq = 100000000; bd->bi_pci_busfreq = 66666666; } + + /* Now turn of the EMAC - otherwise it has a tendency to DMA + crap into the kernel text */ + mtdcr(DCRN_MALCR, MALCR_MMSR); /* 1st reset MAL */ + + while (mfdcr(DCRN_MALCR) & MALCR_MMSR) + ; /* wait for the reset */ + + *em0mr0 = 0x20000000; /* then reset EMAC */ } #endif --
David Gibson | For every complex problem there is a david@gibson.dropbear.id.au | solution which is simple, neat and | wrong. -- H.L. Mencken http://www.ozlabs.org/people/dgibson ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/